The CSC connects three major axonemal complexes involved in dynein regulation

Thomas Heuser, Erin E. Dymek, Jianfeng Lin, Elizabeth F. Smith, Daniela Nicastro

Research output: Contribution to journalArticle

48 Scopus citations

Abstract

Motile cilia and flagella are highly conserved organelles that play important roles in human health and development. We recently discovered a calmodulin- and spoke-associated complex (CSC) that is required for wild-type motility and for the stable assembly of a subset of radial spokes. Using cryo-electron tomography, we present the first structure-based localization model of the CSC. Chlamydomonas flagella have two full-length radial spokes, RS1 and RS2, and a shorter RS3 homologue, the RS3 stand-in (RS3S). Using newly developed techniques for analyzing samples with structural heterogeneity, we demonstrate that the CSC connects three major axonemal complexes involved in dynein regulation: RS2, the nexin-dynein regulatory complex (N-DRC), and RS3S. These results provide insights into how signals from the radial spokes may be transmitted to the N-DRC and ultimately to the dynein motors. Our results also indicate that although structurally very similar, RS1 and RS2 likely serve different functions in regulating flagellar motility.

Original languageEnglish (US)
Pages (from-to)3143-3155
Number of pages13
JournalMolecular biology of the cell
Volume23
Issue number16
DOIs
StatePublished - Aug 15 2012

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ASJC Scopus subject areas

  • Molecular Biology
  • Cell Biology

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